A novel yellow-emitting material, 5,5''-bis{4-[bis(4-methylphenyl)amino]pheny}-2,2':5',2''-terthiophene, for organic electroluminescent devices

A novel amorphous molecular material, 5,5 ''-bis{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2 ''-terthiophene (BMA-3T), has been found to function as a yellow-emitting material in organic electroluminescent (EL) devices. Both the single layer EL device using BMA-3T alone and the double layer EL device consisting of an emitting layer of BMA-3T and an electron-transport layer of tris(8-quinolinolato)aluminum sandwiched between indium-tin-oxide (ITO) and an alloy of magnesium and silver (similar to 10:1) electrodes emitted a bright yellow light resulting from BMA-3T. The double layer EL device showed much better performances than the single layer EL device, exhibiting a maximum luminance of similar to 13 000 cd m(-2) at a driving voltage of 18 V, and a luminous efficiency of 1.1 lm W-1 at a luminance of 300 cd m(-2). (C) 1997 American Institute of Physics.